Simply stating that the Commerce Clause and the Coinage Clause are dead letter law not intended to regulate the exchange of money doesn't make it true. Your interpretation of the law disagrees with more than 200 years of legal consensus on the federal government's power to regulate money exchange within the U.S.--including those of the Founding Fathers themselves.
Counterfeiting has a long and sordid history, and was very much a problem when the Constitution was written. It was, in fact, one of (but not the only) impetuses for the Coinage Clause. See http://www.history.org/Foundation/journal/Summer07/counterfe.... There are plenty of other sources to support this, though this is the only one I found online in my 30 second search. If you want more sources, you're free to visit a library yourself.
Counterfeiting has a long and sordid history, and was very much a problem when the Constitution was written. It was, in fact, one of (but not the only) impetuses for the Coinage Clause. See http://www.history.org/Foundation/journal/Summer07/counterfe.... There are plenty of other sources to support this, though this is the only one I found online in my 30 second search. If you want more sources, you're free to visit a library yourself.